I created a book by importing the text from webpages, this included a number of images which in the ODT file show up as linked to the web version.

When I used W2E to build the EPUB I couldn't see the images, then I realised that they were there but extremely small. When I looked at the xhtml files in the EPUB the images had an attribute of

Code:

style="height:1em"

which explained why they were displaying so small despite the image in the EPUB being of reasonable size.

I have used SIGIL to get rid of the 1em styling and everything seems o.k. however is there some way in which this can be controlled from within W2E when building the EPUB. Image sizes of 1em seem to have very little use.

Take care that the images are anchored to the paragraph, not to the character.

If you use the anchor to the character, the images itself are treated as characters and (in the current version) reduced at 1em.
This allows to use images to substitute symbols, hieroglyphics, runes, signatures and other objects you wish to redim with the font size.

If you read my original post you will see I could easily solve the problem by editing the EPUB, what I wanted to do was not have the problem in the first place. Luke's answer not only gave me the solution but also explained the rationale behind how the extension worked.